Electromagnetic fuel injection spray valve

ABSTRACT

Valve has a disc-shaped armature with a hollow shaft containing a compressed coil spring that holds the valve proper, carried at the end of the shaft, closed, except when the magnet is energized.

United States Patent 1 13,592,392

l inventor Robe" Huber [56] References Cited 21] A I No gg fi'z UNITEDSTATES PATENTS [221 F1121 Jun; 24 1969 1,504,773 8/1924 Marston 239/585[45] Patented July 3,3971 1,664,612 4/1928 French 239/585 1,664,6164/1928 French 239/585 [73] Ass'gnee $32,33 21, Mmemes d f 1,999,2214/1935 Walker et a1. 239/585 x Mum, France 3,070,024 12/1962 Romberg310/18 UX 3,375,380 3/1968 Davis 310/29 3,404,299 10/1968 MacBlane310/29 X 54 ELECTROMAGNETIC FUEL INJECTION SPRAY 'f 7 Benson Wood,

VALVE Assistant ExammerMIchael Y. Mar 9 Chims, 8 Drawing FigsAttorney-Spencer & Kaye [52] US. Cl 239/585,.

123/32, 137/4875, 310/29 ABSTRACT: Valve has a disc-shaped armature witha hollow [51] Int. Cl BOSb l/30 shaft containing a compressed coilspring that holds the valve [50] Field of Search 239/583, roper, carriedat the end of the shaft, closed, except when the 584, 585; 123/32;137/4875; 310/15, 29 magnet is energized.

PATENTED Jun 3 |97l sum 1 or z Invader.-

Obf-H: Hub" 3 M ,Q

3 QRMM S .the induction pipes of the engine, for example.

ELECTROMAGNETIC FUEL INJECTION SPRAY VALVE BACKGROUND OF THE INVENTIONThe invention relates to an electromagnetic fuel injection spray valvefor internal combustion engines.

The electrically operated fuel injection devices of the prior art forinternal combustion engines comprise an electromagnetic fuel injectionspray valve which is opened, in dependence on the r.p.m., byanelectronic control for a predetermined length of time, this period beingdependent on various operating parameters of the engine, includingr.p.m., throttle valve setting, and the suction in the induction pipe.

Fuel under pressure is continuously fed to the housing of theseinjection spray valves. As soon as the magnet coil is energized, thevalve proper, connected to the magnet armature, frees the path to thespray nozzle, and fuel is sprayed into In one fuel injection spray valveof the prior art, the armature is designed as a cylindrical piston thatprojects into a cylindrical magnet coil and is moved against theresistance of a coil spring which biases the valve closed, the springalso being arranged within the magnet coil.

An injection valve of this kind operates satisfactorily at low fuelpressures, such as 2 atmospheres. But at higher fuel pressures, such asatmospheres, the magnetic force is not sufficient to raise the smallcylindrical piston.

In another injection valve of the prior art, the valve embodies adisc-shaped armature and a horseshoe magnet; The magnetic force actingon the armature is substantially greater in this case, permitting higherfuel pressures and, therefore, shorter injection times. A diaphragmspring, held tensed in the valve housing, serves to close the valve. Thespring, however, is very stiff; and it has been observed that thevalve-closing force is greatly dependent on outside factors, such asthermal expansion, so that proper operation of the valve is adverselyaffected.

SUMMARY OF THE INVENTION An object of the invention is to provide a fuelinjection spray valve that possesses the advantage, but notthe'disadvantages, of these two prior art valves, and that is simple andinexpensive to manufacture.

The invention relates to an electromagnetic fuel injection spray valve,including a valve proper, a spray nozzle opened and closed by the valve,a disc-shaped armature for operating the valve, and wherein theimprovement comprises a cylindrical hollow shaft incorporated by thearmature, the valve proper being associated with the free end of theshaft, and a coil spring in the hollow of the shaft for biasing thevalve to its closed position.

The use of a coil spring, for closing the valve, in combina tion with adisc-shaped armature ensures a strong magnetic force and the greatestpossible independence from outside influences.

6O BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described,with reference to the FIGS. of the accompanying drawings, wherein:

FIG. I is a longitudinal section of one embodiment;

FIG. 2 is a view taken along line lI-II of FIG. 1;

FIG. 3 is a view taken along line III-Ill of FIG. 1;

FIG. 4 is a longitudinal section, taken at right angles to that of FIG.1, of an embodiment having a modified armature.

FIG. Sis a view taken along line V-V of FIG. 4;

FIG. 6- is a longitudinal section of another modified annature;

FIG. 7 is a top view of the armature seen in FIG. 6; and

FIG. 8 is a longitudinal section of a third modification of thearmature.

2 DESCRIPTION OF THE PREFERRED EMBODIMENTS The fuel injection sprayvalve shown in FIG. I has a housing comprising two parts I and 2. Withinthe housing is a magnet coil 3, which is wound on a synthetic Plasticformer 4 and surrounds a laminated metal core 5 (see FIG. 2). Thelaminations form a rectangular core (as seen from above) held togetherby the former 4. The four corners of the core touch the round housingpart 1 and hold the core centered within the housing I and 2.

The housing part 2 incorporates a bore 6 for the shaft 7a of adisc-shaped armature 7. The shaft is cylindrical and hollow, and carriesat its lower end a valve'8 that cooperates with a valve seat 9 andperiodically opens and closes the path for the fuel to the spray nozzle10. Within the hollow of the shaft his a coil spring 11, which pressesagainst a slider 12 that, in turn, presses directly against the magnetcore 5. The spring 11 is compressed, and urges the armature 7, thearmature shaft'7a, and the valve 8 at the end of the shaft 7a downwardsagainst the valve seat 9. An annular spacer 13 made of a nonmagneticmaterial, such as a synthetic plastic, is arranged'between the armature7 and the core 5 in order to prevent the latter two from touching eachother and so to reduce the residual magnetism.

The spacer 13 can also be star-shaped, as indicated by the dashed linein-FIG. 3.

A fuel supply line 14 is connected to the housingpart 1', the fuel underabout 20 atmospheres pressure enteringthe interi= or of the housing Iand 2, passing through the bore 15, and entering the annular chamber 16,from which latter it is injected through the spray nozzle 10 and intothe induction pipes of an engine, for example, whenever the valve 8israised from its seat 9. To equalize the pressure, other bores 1 7' and18 connect the hollow of the shaft 7a with the interior'of the housingvl and 2. The magnet armature 7, with its shaft 70, isso fitted in thehousing 1 and 2 that it is raised about 0.1 to 0.2 mm. when ever themagnet coil 3 is energized. A threaded ring I9'press'es' the housingpart 2 directly against the magnet core 5. The necessary compression ofthe spring 11 can be easily adjusted before assembling the fuelinjection valve by suitably dimen-' sioning the slider 12, for example.The stroke of the armatufe 7 is determinal by the dimensions of thehousing part 2 and of the armature with the spacer I3.

The face of the armature adjacent to the core 5 is advantageouslyslightly conical, in order to facilitate movement of the fuel betweenthe armature and the core when the arn'i'a ture rises.

In the embodiment shown in FIGS. 4 and 5, the housing" matures stroke.In this-embodiment, the armature'7 is still-' disc-shapedbut no longercircular in outline; instead two op-' posite segments'have been removedto reduce its weight.

Eddy currents are largely suppressed by incorporating.

milled parallel slots 22 in the armature 7.

In another embodiment shown in FIGS. 6 and-'7', the armature 7includesthe hollow shaft 7a with its compression spring 11 andlaminations 24 riveted onto a crosspiece 23, the

laminations 24 constituting the disc-shaped armature 7. Thismanner offorming the armature 7'of-laminations also reduces the appearance ofeddy currents.

In still another embodiment, shown in FIG. 8, the hollow shaft 7a withits valve 8 is made of steel, and thedi'sc-shaped armature 7 is-made ofsoft iron and cemented or'w'elded to the shaft 7a. The interior of theshaft 7a houses-the-compression spring 11, which presses against anintermediate ri'ngpressin'g against theslider 12, which contacts themagnet c'ore.

Although thepreferred embodiments of the invention have been described,the scope of, and the breadth of protection af forded to, the inventionare limited solely by the appended claims.

I claim:

1. An electromagnetic fuel injection spray valve, including a valveproper, a spray nozzle opened and closed by said valve proper, adisc-shaped armature connected to said valve proper for operating thelatter, and wherein the improvement comprises a cylindrical hollow shaftincorporated by said armature, said valve proper being associated withthe free end of said shaft, a coil spring in the hollow of said shaftfor biasing said valve proper to its closed position, a slider (12)slidable in the hollow of said shaft, and a magnet core, and whereinsaid coil spring presses on said slider against said core.

2. The injection valve as defined in claim 1, including a cylindricalhousing for the fuel injection valve, and wherein said core is withinsaid housing and has the form of alaminated magnet core that isrectangular in cross section, and the four corners of said core touchsaid housing to center said core inside said housing.

3. The injection valve as defined in claim 2, including a magnetarmature, and wherein a face of said armature lies ad jacent to saidcore and is cone shaped.

4. The injection valve as defined in claim 1, including a housing forthe fuel injection valve, and a plurality of bores (l7, 18) forconnecting the hollow of said shaft to the interior of said housing.

5. The injection valve as defined in claim 1, including a housing forthe fuelinjection valve, and wherein part (2) of said housing guidessaid armature in its movement and is in direct contact with said core.

6, The injection valve as defined in claim 1, wherein the disc-shapedpart of said armature is substantially rectangular and has two straightand two arcuate sides.

7. The injection valve as defined in claim 6, wherein the disc-shapedpart of said armature has parallel slots to reduce eddy currents.

8. The injection valve as defined in claim 1, wherein the disc-shapedpart of said armature is composed of riveted laminations to reduce eddycurrents.

9. The injection valve as defined in claim 1, wherein the disc-shapedpart of said armature is made of soft iron and said shaft is made ofsteel, and further including means for fastening together these twoarmature parts.

UEQITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 3 592392 Dated July 13th 1971 Inventor(s) Robert Huber It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In the heading of the patent, line 2, after "Zumikon" insertSwitzerland; line 7, delete "l".

Signed and sealed this ll th day of December 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,J'R. ROBERT GOTTSCHALK Attesting Officer ActingCommissioner of Patent;

FCRM F'O-105O 110-69) UscoMM-Dc 60376.:69

9 U 5 GOVERNMENT PI'HNYING OFFICE 19.9 OJ66-334

1. An electromagnetic fuel injection spray valve, including a valveproper, a spray nozzle opened and closed by said valve proper, adisc-shaped armature connected to said valve proper for operating thelatter, and wherein the improvement comprises a cylindrical hollow shaftincorporated by said armature, said valve proper being associated withthe free end of said shaft, a coil spring in the hollow of said shaftfor biasing said valve proper to its closed position, a slider (12)slidable in the hollow of said shaft, and a magnet core, and whereinsaid coil spring presses on said slider against said core.
 2. Theinjection valve as defined in claim 1, including a cylindrical housingfor the fuel injection valve, and wherein said core is within saidhousing and has the form of a laminated magnet core that is rectangularin cross section, and the four corners of said core touch said housingto center said core inside said housing.
 3. The injection valve asdefined in claim 2, including a magnet armature, and wherein a face ofsaid armature lies adjacent to said core and is cone shaped.
 4. Theinjection valve as defined in claim 1, including a housing for the fuelinjection valve, and a plurality of bores (17, 18) for connecting thehollow of said shaft to the interior of said housing.
 5. The injectionvalve as defined in claim 1, including a housing for the fuel injectionvalve, and wherein part (2) of said housing guides said armature in itsmovement and is in direct contact with said core.
 6. The injection valveas defined in claim 1, wherein the disc-shaped part of said armature issubstantially rectangular and has two straight and two arcuate sides. 7.The injection valve as defined in claim 6, wherein the disc-shaped partof said armature has parallel slots to reduce eddy currents.
 8. Theinjection valve as defined in claim 1, wherein the disc-shaped part ofsaid armature is composed of riveted laminations to reduce eddycurrents.
 9. The injection valve as defined in claim 1, wherein thedisc-shaped part of said armature is made of soft iron and said shaft ismade of steel, and further including means for fastening together thesetwo armature parts.